Telecommunications apparatus and methods for half-duplex and full-duplex

Abstract

A telecommunications system including plural base stations and plural terminal devices communicating over a radio interface having a radio frame structure including radio subframes each including plural symbols. At least one symbol in each radio subframe is used to support a physical shared channel and at least one symbol in each radio subframe is used to support a physical control channel associated with the physical shared channel. A symbol at the end of each radio subframe is used to support the physical shared channel for communication links between a base station and a terminal device operating in a full-duplex mode, but the corresponding symbol is used to support a separate physical channel, for example an additional low-rate channel, for communication links operating in a half-duplex mode. Thus, transmission resources that would normally be idle in a half-duplex system compared to a full-duplex system can be re-used for another channel.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to methods, systems and apparatus for transmitting data in mobile telecommunications systems.[0002]Third and fourth generation mobile telecommunications systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture are able to support more sophisticated services than simple voice and messaging services offered by previous generations of mobile telecommunications systems.[0003]For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy third and fourth generation networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to increase rapidly.[0004]FIG. ...

AI Technical Summary

Benefits of technology

The invention provides a telecommunications system with a plurality of base stations and terminal devices that communicate over a radio interface. The system uses a radio frame structure with symbols that support a physical shared channel and a physical control channel associated with the shared channel. The system also uses an additional physical channel that supports communications with a subset of the terminal devices, such as machine-type communication devices or terminal devices in a dormant state. The additional physical channel can be used for broadcast / multicast signaling or to indicate the availability of an additional carrier. The symbols associated with the additional physical channel are treated as a group as a radio subframe associated with the channel. Overall, the invention provides a more efficient and flexible way to communicate data in a telecommunications system.

Problems solved by technology

What is more, it is generally not possible for a terminal device to switch instantaneously from reception to transmission.

Even for terminal devices having low switching times and which are relatively close to the base station and (hence subject to relatively short propagation delays), there will be at least one idle symbol.

This represents a loss of around 7% of the available physical transmission resources.

However, this reduces the maximum data rate that can be sustained for a given terminal device, and furthermore introduces complexity into the scheduling procedures resulting in reduced scheduling flexibility.

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